Castro was 0-for-9 in two games heading into Thursday's matinee against the Pirates.
• In the 13th inning Wednesday, the game was tied and the Pirates had loaded the bases. What to do? Renteria had a meeting on the mound, and called left fielder Junior Lake in.
"I brought him in, and when we were on the hill, I said, 'Where do you feel the most comfortable?'" said Renteria, who wanted to go with a five-man infield. "I knew he had played third base. He looked over [at third]. I wanted to validate it. That was an easy decision, [him having played] third base in the past."
The move worked, as Clint Barmes hit the ball to Lake, who started a 7-2-3 double play.
The Cubs escaped any damage then, but lost, 4-3, in 16 innings.
• Emilio Bonifacio is the first player in the last 100 years to start his Cubs career with at least four hits in each of his first two games.
"I feel pretty good at the plate," Bonifacio said. "I've been having good results."
At one point Wednesday, Bonifacio had five hits, and the Pirates had five hits.
"I just try to get a base hit every at-bat," he said. "You have to stay positive. You want to get the win after you play that long."
• The Cubs' 16-inning marathon game against the Pirates was the 100th game of at least 15 innings in franchise history, and the longest since an 18-inning contest on Aug. 15, 2006, in Houston.
Carrie Muskat is a reporter for MLB.com. She writes a blog, Muskat Ramblings, and you can follow her on Twitter @CarrieMuskat. This story was not subject to the approval of Major League Baseball or its clubs.